Dear all,

It's been quite sometime that I've been dealing with the issue of planning a path for a manipulator while keeping its gripper parallel to the ground using Moveit!. As I set some path constraints to fix the orientation of the gripper, Moveit would no longer be able to generate the right trajectory and it spits out "Fail: ABORTED: No motion plan found. No execution attempted."

I went through lots of googling and tried whatever I found but none of them worked. It seems there are also other people dealing with the same problem but no one has mentioned a solution for it yet. I was wondering if anybody could help me over this. Is there any way to achieve this using Moveit? The manipulator that I'm working with is Franka Emika.

Thanks in advance.

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Update:

The only way which came to my mind for fixing the gripper's orientation while moving was using

geometry_msgs::PoseStamped target_pose;
moveit_msgs::OrientationConstraint ocm;
ocm.link_name = "gripper";
ocm.header.frame_id = "base_link";
ocm.orientation.x = -0.0000;
ocm.orientation.y = -0.0000;
ocm.orientation.z = 0.718;
ocm.orientation.w = 0.696;
moveit_msgs::Constraints test_constraints;
test_constraints.orientation_constraints.push_back(ocm);
group.setPathConstraints(test_constraints);
moveit::planning_interface::MoveGroupInterface::Plan move_plan;
group.setPoseTarget(target_pose0);
success = group.plan(move_plan
group.move();

However, this results in no plan being generated. Everything works fine without setting constraints, but Moveit! would stop generating motion plans as soon as I set any constraints.

The same problem has been mentioned in this post as well: https://answers.ros.org/question/271489/path-constraints-not-keeping-end-effector-in-fixed-configuration-move/

I was reading through this google forum also, but it didn't help. https://groups.google.com/forum/#!topic/moveit-users/-ZkAMG-1DQ4

I also tried increasing the planning time and changing the values for the constraints as well, since I thought that I might put wrong values for the constraints which would result in no plan to be found, but none of them worked.

I appreciate if any anybody has any solution for this. Thanks

geometry_msgs::PoseStamped target_pose;
moveit_msgs::OrientationConstraint ocm;
ocm.link_name = "gripper";
ocm.header.frame_id = "base_link";
ocm.orientation.x = -0.0000;
ocm.orientation.y = -0.0000;
ocm.orientation.z = 0.718;
ocm.orientation.w = 0.696;
moveit_msgs::Constraints test_constraints;
test_constraints.orientation_constraints.push_back(ocm);
group.setPathConstraints(test_constraints);
moveit::planning_interface::MoveGroupInterface::Plan move_plan;
group.setPoseTarget(target_pose0);
success = group.plan(move_plan
group.move();